NEET 2026
- Exam
- NEET
- Year
- 2026
- Subject
- Biology
- Chapter
- Chapter
NEET 2026 · Biology · Chapter
In the development of transgenic tobacco plants resistant to the...
In the development of transgenic tobacco plants resistant to the nematode Meloidogyne incognita, Agrobacterium vectors are used to introduce nematode-specific genes into the host. Which of the following correctly explains the molecular basis of this defense strategy?
Options
- AThe introduced DNA produces a crystalline toxic protein that creates pores in the nematode's midgut.
- BThe introduced DNA produces both sense and anti-sense RNAs in the host cells that bind to form a double-stranded structure.
- CThe introduced DNA modifies the host plant's ribosomes to completely prevent the translation of any foreign mRNA.
- DThe host plant is stimulated to produce specific antibodies that neutralize the nematode's digestive enzymes.
Correct answer
B. The introduced DNA produces both sense and anti-sense RNAs in the host cells that bind to form a double-stranded structure.
Step-by-step solution
The defense strategy used in transgenic tobacco plants against the nematode Meloidogyne incognita is based on RNA interference (RNAi).
Using Agrobacterium vectors, nematode-specific genes are introduced into the host plant. The introduced DNA is designed in such a way that it produces both sense and anti-sense RNAs in the host cells.
These two RNAs are complementary to each other and bind to form a double-stranded RNA (dsRNA). This dsRNA initiates RNA interference and silences the specific mRNA of the nematode, thereby preventing the translation of essential nematode proteins and leading to its death.
Option (A) describes the mechanism of Bt cotton (Cry proteins) against insects, not RNAi.
Option (D) is incorrect as plants do not produce antibodies.
Answer: The introduced DNA produces both sense and anti-sense RNAs in the host cells that bind to form a double-stranded structure.
Using Agrobacterium vectors, nematode-specific genes are introduced into the host plant. The introduced DNA is designed in such a way that it produces both sense and anti-sense RNAs in the host cells.
These two RNAs are complementary to each other and bind to form a double-stranded RNA (dsRNA). This dsRNA initiates RNA interference and silences the specific mRNA of the nematode, thereby preventing the translation of essential nematode proteins and leading to its death.
Option (A) describes the mechanism of Bt cotton (Cry proteins) against insects, not RNAi.
Option (D) is incorrect as plants do not produce antibodies.
Answer: The introduced DNA produces both sense and anti-sense RNAs in the host cells that bind to form a double-stranded structure.